Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8cc639b06dbad52…

MALICIOUS

PDF

82.6 KB Created: 2021-09-17 03:02:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4bf4d469732fe0ba28d7b079a5c8a1a3 SHA-1: 9385aa29cdb599ccd10b72b674a001857e021205 SHA-256: c8cc639b06dbad527ef27787621ae5ee5dec56e7b21fded5d5c17e83212d7b3b
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF file flagged by ClamAV as 'Pdf.Phishing.Trojan' and by an ML classifier as malicious. It contains embedded JavaScript and a large number of external URIs, many of which point to disposable hosting or link farms, indicating a phishing or malware distribution attempt. The embedded JavaScript likely facilitates the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://chcial.ru/uplcv?utm_term=piano+tiles+2+android PDF link annotation
    • https://tatsolarlight.com/uploads/files/23404090922.pdfIn PDF document text
    • http://dansensvenner.dk/imagesfile///jizijozujonux.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/4851590201.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/16143694029c83---87600277474.pdfIn PDF document text
    • https://binarbaid.com/public_html/userfiles/file/wawepo.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/xemolak.pdfIn PDF document text
    • http://ctnphrae.com/ckfinder/userfiles/files/80357161988.pdfIn PDF document text
    • http://ore-processing.ru/d/files/penop.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/20855011767.pdfIn PDF document text
    • https://bulendengin.com/upload/ckfinder/files/58166139950.pdfIn PDF document text
    • http://we2meeting.com/ckfinder/userfiles/publics/files/fazalereratesuwaralimakat.pdfIn PDF document text
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/71479402794.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/zajere.pdfIn PDF document text
    • http://kozszemle.hu/uploads/files/84621849196.pdfIn PDF document text
    • https://www.hmgfinance.com/ckfinder/userfiles/files/wumeled.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/49870368402.pdfIn PDF document text
    • http://www.hydro-tg.pro/upload/file/gijotisol.pdfIn PDF document text
    • http://ildungrice.com/fileupload/fckeditor/file/vezekuzopamakejexexot.pdfIn PDF document text
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/rawokujow.pdfIn PDF document text
    • http://wellogo.in/userfiles/file///rasozij.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/36903078446.pdfIn PDF document text
    • http://daeryuhealthcare.com/ckupload/files/70462379394.pdfIn PDF document text
    • https://tgvl.in/uploads/fck/files/botope.pdfIn PDF document text
    • https://artistprasanna.com/userfiles/file/37285483041.pdfIn PDF document text
    • https://strategieb2b.ca/userfiles/file/masevarebogubivomivo.pdfIn PDF document text
    • https://retrofitoman.com/ckfinder/userfiles/files/gelasa.pdfIn PDF document text
    • http://motorlustor.net/userfiles/file/27606820442.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d387.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD387 21420 bytes
SHA-256: ca4191a85e772edc19298d70ff44ddb3a9fd869e74c29bb6cf8663822a4ea4e3
font_01_sfnt_off00010cba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBA 10364 bytes
SHA-256: c3191cd5661bc9cc1fe94332263a33727ddbee73adbeeb5c43fe28fca17e5bcd
font_02_sfnt_off00012450.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12450 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1